The invention relates generally to sootblowers used for cleaning surfaces that are subject to ash fouling. Specifically, the invention involves multiple rake sootblowers with internal valving manifolds.
In the design of sootblowers for any particular application, there are three basic goals. The first goal is to provide complete coverage of the entire area that is subject to ash fouling. Second, sufficient sootblowing media pressure should be available at each nozzle. The third goal is to minimize the space requirements for the stroke of the sootblowers to provide the complete coverage.
In the case of a long but narrow area such as heat exchanger plates, there are two common rake-type sootblower designs which are often used. One involves the use of a plurality of single rake sootblowers, usually side by side, to cover a long, narrow area. Each one of the rakes only needs a short stroke to cover its assigned area. This requires an actuator for each rake and the rakes are operated one at a time so that each rake has sufficient sootblowing pressure. The other design is the half-track design. This usually uses two rakes extending into a long area from opposite ends with each rake covering one half of the long, narrow area although there are other variations. This design requires one actuator for each of the two rakes. There are usually more nozzles in each of the two rakes than with the single rake design which results in reduced sootblowing pressure at each nozzle. Therefore, it can be seen that each of these designs has its limitations and disadvantages.